The #StopCensoringMotherhood hashtag fights against social media sites that keep removing pictures of “women showcasing themselves in a nonsexual way." Facebook, however, defends its strict policy against any child nudity.

Since starting the project, Jackson and her partner Laura Weetzie Wilson have photographed nearly 500 women, filmed a documentary, and signed a three-book deal — all in an effort to embrace how the body changes after pregnancy.

As part of the project, Jackson and Wilson have posted images of women's postpartum bodies (like the ones above and below) on their Facebook and Instagram accounts. But now, after images that include nonsexual nudity or child nudity have been removed from their social media accounts, they are struggling to keep 4th Trimester Bodies alive.

The project's Instagram account has been shut down nine times, Jackson said. And she's been locked out of her Facebook account multiple times.

Instagram's policies indicate that accounts posting nudity or mature content will be disabled. However, it sometimes seems arbitrary what images remain on the site.

Jackson noted that pictures of celebrities breast-feeding or posing on beaches in bikinis are often not removed — not to mention that overtly erotic photos live on both platforms. Jackson said she recently found the #sxy hashtag on Instagram, which aggregates thousands of sexual images, including images of adults engaged in sexual acts.

"They don't take that stuff down," Jackson said. "But they seem to have a problem with women showcasing themselves in a nonsexual way."

Top row: 4th Trimester Bodies pictures removed from Instagram. Bottom row: Pictures on Instagram of celebrities with their children that were not removed.

Jackson said that after the pages were disabled in the fall, "things were pretty quiet for several months." Although an occasional photograph would get removed, Jackson spent that time focusing on her documentary and book deal.

Until a few weeks ago.

Jackson began to notice that more and more pictures were being taken down. The project's Instagram account was missing about 75 images, and she had never received notifications that the pictures had been removed.

"On Facebook we get notifications if our pictures get taken down, but sometimes we don't even realize that our Instagram pictures are disappearing without any explanation," said Jackson.

After digging around, Jackson and the 4th Trimester Bodies project found that they were not alone: About 150 other women had been affected by Instagram's and Facebook's policies, Jackson said. Some had posted pictures of their children with some nudity, and others had posted pictures of themselves breast-feeding their kids, which Facebook or Instagram had removed.

Along with the other mothers affected, Jackson created the #StopCensoringMotherhood hashtag to bring more attention to the issue.

While Jackson can continue working on her documentary and book deals whether or not the organization's images remain on social media sites, she said the entire process has been very distracting.

"The time it's taken to try to keep our work up is exhausting," she said. "We've spent weeks trying to get our images out there and focusing on this and getting our PR team and legal team involved in this fight. It is inhibiting our work and time that should be spent elsewhere."

Speaking to BuzzFeed, a spokesperson for Facebook and Instagram did not comment on specific instances of pictures being removed, but was aware of the situation. The spokesperson said that both websites allow for pictures of breast-feeding, adding:

We have always allowed breast-feeding photos – it is natural and beautiful and we know that it's important for mothers to share their experiences with others on Facebook and Instagram.

The spokesperson also said that nudity of any kind is strictly prohibited "to help keep children safe online," but admitted that employees sometimes make errors in removing images:

"It is very hard to consistently make the right call on every photo that may or may not contain nudity that is reported to us, particularly when there are billions of photos and pieces of content being shared on FB everyday, and that has sometimes resulted in content being removed mistakenly," the spokesperson told the Huffington Post.

A spokesperson for Facebook and Instagram said that in May 2014, it modified its policies to better "examine" pictures of nudity, which it hopes will enable more of the 4th Trimester Photos to remain on the site:

What we have done is modified the way we review reports of nudity to help us better examine the context of the photo or image. As a result of this, photos that show a nursing mothers' [sic] other breast will be allowed even if it is fully exposed, as will mastectomy photos showing a fully exposed other breast. We hope that this improvement will enable more breastfeeding and post-mastectomy photos to remain on the service even after they are reported.

Jackson, however, doesn't seem to believe that new policy will change anything.

"Many of the images were removed after that date," she told BuzzFeed. "I don't believe the change has led to our images being any more protected."